(19)

(11)

EP 3 881 508 A1

(12)

(43) Date of publication: 22.09.2021 Bulletin 2021/38 (21) Application number: 18807231.8 (22) Date of filing: 13.11.2018

(51) International Patent Classification (IPC):  H04L 12/857(2013.01) H04L 29/06(2006.01) (52) Cooperative Patent Classification (CPC): H04L 47/2491; H04L 69/08 (86) International application number: PCT/EP2018/081046 (87) International publication number: WO 2020/098917 (22.05.2020 Gazette 2020/21)

(84) Designated Contracting States: AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR Designated Extension States: BA ME Designated Validation States: KH MA MD TN (71) Applicant: ABB Schweiz AG 5400 Baden (CH)	(72) Inventors: ÅKERBERG, Johan 725 95 Västerås (SE) NEANDER, Jonas 724 60 Västerås (SE) GADE, Jörgen 725 92 Västerås (SE) (74) Representative: Kransell & Wennborg KB  P.O. Box 27834 115 93 Stockholm 115 93 Stockholm (SE)